Energy From Enzymes: Bio Batteries are on the way

Batteries put the mobile in mobile devices like iPhones and laptop computers. Freed from power cords and wall sockets, they allow us to enjoy our devices just about anywhere. Unfortunately the materials used to power the batteries eventually destroy them, moreover, many of these materials are heavy metals like mercury, lead, lithium, cadmium, and nickel that are hazardous to the environment which is why it is important to dispose of them properly.

There’s a solution on the horizon – the “bio” or organic battery.

Like traditional batteries, bio or organic batteries use chemical reactions to produce energy, however the chemicals used to create this energy is what makes them special because they use the same chemical reactions to produce energy as living organisms do, hence the name.

At a recent Eco-Products 2011 exhibition held in Tokyo, Japan, Sony unveiled their latest bio battery where it created a sensation by powering a small propeller using pieces of cardboard soaked in a special fluid. Enzymes in the fluid were used to decompose the cardboard (carbohydrates), turning it into a sugar called glucose, which then mixes with oxygen creating electrons and hydrogen ions and finally turned into power.

Like a conventional fuel cell battery, Sony’s Bio Battery basically consists of an anode, cathode, electrolyte, and separator. The enzymes are used as catalysts for the anode and cathode. Electronic mediators, which transfer electrons between enzymes and electrodes, are fixed on the anode and cathode.

In example explained above, the cardboard is only a source of glucose sugar which is the real fuel that provides the power. The glucose is broken down on the anode side of the battery producing protons and electrons, the protons are transferred to the cathode side of the battery and the electrons are transported to the anode side of the battery through the mediator, which transfers them to the external circuit. The cathode uses the enzymes to drive an oxygen-reduction reaction which ultimately produces water using both the protons and the electrons.

While the idea isn’t new because the first bio batteries were created during the 1960s, however there was difficulty in transporting the electrons and keeping the system stable enough to produce electricity. As a result, Sony’s breakthrough is bringing organic batteries closer to becoming a viable alternative to conventional dry and wet batteries. .

Since then, there have been many advances in the area of organic batteries as many corporations, universities, governments, and research foundations are working to create practical batteries that are powered by organic compounds. Sony has been at the forefront of developing and testing new types of bio batteries, not only did they develop the propeller powered by cardboard but also used bio batteries to power a Walkman as well as a remote controlled toy car. Today scientists are experimenting with all types of organic substances – from waste paper, soda pop, and beer to body fluids like blood and urine to produce electricity.

The main advantage and reason for developing bio batteries are their Eco-friendliness as they don’t use potentially harmful metals or chemicals in their construction or operation but rather glucose which is extremely stable and completely safe to handle, store and transport. The carbohydrates used to produce the glucose (like cardboard) are completely organic as they are produced by plants through the process of photosynthesis. These carbohydrates are carbon neutral and do not contribute to increases in carbon dioxide or other greenhouse gases.

While there have been many exciting developments in the area of bio-batteries, it will probably be several years before we see them replacing the traditional nickel-cadmium or lithium-ion batteries but as environmentally friendly and renewable energy sources become more important, research will continue into developing alternative forms of energy like bio batteries. Who knows – someday we may be powering our laptops and mobile phones using waste paper and soda pop.